1. Field of the Invention
The present invention is directed to a carbonate spring bath system, and more particularly to, such a system for creating a bath water dissolved with carbon dioxide [CO.sub.2 ] gas and supplying the same to a bathtub.
2. Background of the Invention
A carbonate spring bath system has been already proposed in Japanese Patent Publication [KOKAI] No. 3-131259 in which CO.sub.2 gas is dissolved together with a small amount of an air into a bath water to be supplied into a bathtub so that a user can enjoy a carbonate spring bath in one's home. The system includes a booster pump for circulating the bath water from and into a bathtub as well as for dissolving the CO.sub.2 gas and air into the bath water at an elevated pressure. An accumulator is provided downstream of the pump in order to separate undissolved or excess amount of the CO.sub.2 gas and the air from the bath water and feed the bath water, thereby assuring to feed the bath water into which the CO.sub.2 gas and the air are successfully dissolved, and therefore preventing the undissolved CO.sub.2 and air from being fed into a bathtub. The separation of the undissolved CO.sub.2 and air is essentially in that if the undissolved gas is fed along with the bath water into the bath, large bubbles of the CO.sub.2 gas and the air are very likely to occur in the bathtub to thereby give off a large proportion of the CO.sub.2 gas, i.e., reduce the content of the dissolved CO.sub.2 gas, which greatly lowers the effect of the carbonate spring bath. However, with the use of the accumulator, there remains a problem in that the CO.sub.2 gas separated as the undissolved gas in the accumulator is discharged wastefully. Further, the system is capable of dissolving the air in the bath water such that the dissolved air can form micro bubbles in the bath water after introduced into the bathtub and depressurized therein. To obtain an adequate amount of the air, the system is designed to best utilize a combustion gas of a hydrocarbon fuel as a source of the mixture gas of the CO.sub.2 gas and the air. However, when the system is modified to receive the CO.sub.2 gas from a pure CO.sub.2 source, for example, a CO.sub.2 bottle or chemical apparatus of forming a pure CO.sub.2 gas by chemical formation, the system is not capable of producing an air bubbling.